High bipolar voltages, for example ±270 V, are frequently required in aircraft. Generators and corresponding rectifiers are conventionally used to provide voltages of this type.
EP 2 624 433 A1 discloses two non-insulating DC-DC converter units, connected in parallel, having a neutral point, which is galvanically separated from a neutral point of the DC-DC converter unit, of an AC voltage filter, connected downstream from the DC-DC converter units, for supplying DC voltage generated by photovoltaic cells to an AC voltage network.
US 2009/0085537 A1 discloses a non-insulating boost converter for DC voltages, in which a unipolar input DC voltage is converted into a bipolar output DC voltage by two coupled boost converter units.
The document A. Lücken, H. Lüdders, T. Kut, S. Dickmann, F. Thielecke, D. Schulz: “Analyse einer neuartigen elektrischen Konverterarchitektur zur Integration von Brennstofzellen auf Gesamtsystemeben” [Analysis of a new electric converter architecture for the integration of fuel cells at the overall system level], German Aeronautics and Astronautics Conference 2012, Berlin, German Society for Aeronautics and Astronautics, Bonn, 2012, discloses a fuel cell system comprising two fuel cell stacks, arranged connected in series, which respectively supply positive and negative output voltages for a DC-DC converter module for generating positive and negative HVDC voltages for a bipolar DC voltage network in an aircraft.
U.S. Pat. No. 7,087,327 B2 discloses a fuel cell matrix for use in a series or parallel combination for supplying electrical power to a power network. U.S. Pat. No. 7,799,481 B2 discloses connection options for fuel cell stacks for setting the power output.